A major power cut in west London affected supplies to thousands of homes, disrupted road and underground traffic and caused widespread changes to BBC radio and television programmes on Tuesday evening.

The power cut was tracked down to a sub-station which failed in Shepherds Bush and supplies were not restored for some hours.

Over 20,000 homes and shops in the area were affected and some traffic lights failed.

Power was lost at the BBC's Television Centre forcing some programmes including the Six O'clock News off air.

News journalists were sent to studios in Birmingham and south London so coverage on all television and radio channels was disrupted as little as possible.

Television Centre produces the bulk of BBC programmes

Power went off at 1700 BST triggering fire alarms at TV Centre. Thousands of staff were evacuated as a safety precaution.

News teams were allowed to leave a skeleton staff in the building to keep services running as best as they could - including News Online.

Emergency generators kicked in but many lights and computers ceased to function around 1820 BST.

BBC News 24, BBC Two and Radio 4 were forced off air and had to transmit back-up programmes.

News Online staff stayed put in their Television Centre newsroom

The Six O'clock News went off air for a few minutes, along with some regional programmes across the country.

"It just went and there was a big fizzle in the studio, and then a big bang," said Six O'Clock News presenter Huw Edwards.

"We were left sitting in complete darkness."

The BBC's coverage of England's vital Euro 2000 match against Romania was not interrupted.

Thousands lose power

A spokesman for the BBC said scheduled programmes were being restored as power gradually came back on.

"We are hoping to still put out our Panorama special on football hooliganism at Euro 2000 at the scheduled time, despite valuable editing time being lost," he said.

London Underground services were also affected, with the two stations at Shepherds Bush closing down during the evening rush hour.

We regret what has happened but incidents like this are extremely rare

London Electricity

A LU spokesman said this was a result of defective safety equipment but did not know if this had been caused by the power cut.

London Electricity said the exact cause of the fault was not known but engineers worked throughout the evening to restore power by 2145 BST.

"We regret what has happened but incidents like this are extremely rare," he said.